Illuminated electric toothbrushes emitting high luminous intensity toothbrush

ABSTRACT

An electric toothbrush has a handle, a neck attached to the handle, and a head attached to the neck. The head has a movable bristle holder having a plurality of bristles extending therefrom. The toothbrush further includes a light emitting element disposed in the bristle holder, wherein the light emitting element is capable of providing light having wavelengths between about 390 nm to about 770 nm and having a radiometric power of between about 5 mW/cm 2  to about 200 mW/cm 2 .

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.10/832,168 filed on Apr. 4, 2004, which claims the benefit of U.S.provisional application Ser. No. 60/501,266 filed Sep. 9, 2003, each ofwhich is herein incorporated by reference.

FIELD OF THE INVENTION

The present invention relates to illuminated electric toothbrushes thatutilize a light emitting diode, particularly a light emitting diode thatilluminates the brushing area.

BACKGROUND OF THE INVENTION

Lighted toothbrushes have traditionally been manual brushes having alight disposed on or in the handle of the toothbrush with fiber opticscarrying the light from the handle to the head of the toothbrush.However, light that is transmitted by fiber optics often diminishes inluminous intensity and/or flux density as it is transmitted. Therefore,it was desired to have a light disposed in or on the head of thetoothbrush such that no fiber optic materials are necessary to transmitthe light. Additionally, it was desired to have an electric lightedtoothbrush.

In order for a light to be disposed on the head of a toothbrush,especially an electric toothbrush, the size must be minimized to allowsufficient space for bristles, and sufficient space for the mechanics ofthe electric toothbrush. A standard light emitting diode may be of theproper size; however such a device may not be able to deliver lighthaving sufficient luminous intensity and/or flux density to provide anoral care benefit. A high power non-standard light emitting diode may beable to deliver the desired luminous intensity and/or flux density.However, the high power diodes use a high current level, and thusgenerate a high level of heat. Generating a high level of heat in theoral cavity can overheat the pulp chamber, which can result in pulpitisor other damage to oral tissues. Accordingly, there is a need for anilluminated electric toothbrush comprising a light emitting diode thatemits light having a luminous intensity of at least about 7 candelasand/or flux density of at least about 30 mW/cm² which can safely be usedsafely in the oral cavity without damaging the teeth and/or other oralsurfaces.

SUMMARY OF THE INVENTION

In some embodiments, an electric toothbrush constructed in accordancewith the present invention comprises a handle, a neck attached to thehandle, and a head attached to the neck. The head has a movable bristleholder having a plurality of bristles extending therefrom. A lightemitting element is disposed in the bristle holder, wherein the lightemitting element is capable of providing light having wavelengthsbetween about 390 nm to about 770 nm and having a radiometric power ofbetween about 5 mW/cm² to about 200 mW/cm².

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may take physical form in certain parts and arrangementsof parts, embodiments of which will be described in detail in thisspecification and illustrated in the accompanying drawings which form apart hereof, and wherein:

FIG. 1 is a cross-sectional view of a light emitting diode.

FIG. 2 is a cross-sectional view of a light emitting diode having morethan one light emitter, and a single optical output.

FIG. 3 is a perspective view of an illuminated electric toothbrush inaccordance with the present invention.

FIG. 4 is a top planar view of the electric toothbrush of FIG. 3.

FIG. 5 is a cross-sectional side elevational view of the electrictoothbrush of FIG. 3.

FIG. 6 is a cross-sectional side view of the head of the electrictoothbrush.

FIG. 6 a is a cross-sectional side view of the head of the electrictoothbrush.

FIG. 7 is a partial front elevational view of a head and neck of anotherembodiment of the present invention.

FIG. 8 is a partial front elevational view of a head and neck of yetanother embodiment of the present invention.

FIG. 9 is a partial front elevational view of a head and neck of stillanother embodiment of the present invention.

FIG. 10 is a partial front elevational view of a head and neck of yetanother embodiment of the present invention.

FIG. 11 is a partial front elevational view of a head and neck of yetanother embodiment of the present invention.

FIG. 12 is a partial front elevational view of a head and neck of stillanother embodiment of the present invention.

FIG. 13 is a perspective view of another embodiment of the illuminatedelectric toothbrush of the present invention in which the toothbrushincludes a head and neck that can be separated from the handle.

FIGS. 14 and 15 are partial side elevational views illustratinginstallation of a replaceable head and neck onto a handle or bodyportion of the illuminated electric toothbrush of FIG. 11.

FIG. 16 is a schematic of an electrical configuration suitable for usewith the present invention.

FIG. 17 is a graph of the spectral distribution for a variety of colorsfor light-emitting diodes that are suitable for use with the presentinvention.

FIG. 18 is a graph of the spectral distribution for a light-emittingdiode that emits a white light that is suitable for use with the presentinvention.

FIG. 19 is a graph illustrating a light radiation pattern suitable foruse with the present invention.

FIG. 20 is a diagram illustrating the geometry of the void between thelight emitting diode and the surface to be exposed to light.

FIG. 21 is a diagram illustrating the test method for measuring averageintensity of the light within a particular solid angle.

FIG. 22 is a diagram illustrating the test method for measuring theaffect of the illuminating electric toothbrush on the temperature at thesurface of the teeth.

DETAILED DESCRIPTION OF THE EMBODIMENTS

All printed publications, patents, and patent applications referencedherein are incorporated herein by reference. Generally, the presentinvention relates to an electric toothbrush having one or morelight-emitting diodes (“LED”) disposed on or in the head of the electrictoothbrush. More specifically, the electric toothbrushes are used inpersonal hygiene to clean one's teeth and gums using a motorizedmovement, while the LEDs illuminate the region of brushing, includingthe teeth and/or gums. Additionally, the LEDs can provide an oral carebenefit, such as whitening.

As used herein, the term “light” is intended to encompass the spectrumof both visible and non-visible (e.g., ultraviolet and infra-red) light.There are two systems for measuring light: radiometry and photometry,wherein radiometry is measurement of electromagnetic radiation withinthe frequency range between 3×10¹¹ and 3×10¹⁶ Hz and photometry is themeasurement of electromagnetic radiation that is detectable by the humaneye. As known in the art, radiometric units include: Energy (Newtonmeter or joules), Power or Radiant Flux which is the flow of Energy withrespect to time (joules/second or watts), Irradiance or Flux Densitywhich is power per unit area (watts/m²), Radiant Intensity which ispower per unit solid angle (watts/steradian), and Radiance which is thepower per unit projected area per unit solid angle (watts/m²-steradian).Equivalent photometric units include: Power or Luminous Flux (lumen) andLuminous Intensity (lumen/sr or candela). Another characteristics of thelight that will be discussed is the viewing or half angle. As describedherein the half angle is two times the included angle (in degrees)between the peak and the point on one side of the beam axis at which theluminous intensity is fifty percent of the maximum or half of the beamangle. Yet another characteristic that will be discussed hereafterrelates to the amount of heat or Emission Temperature (Celsius) which isgenerated by an LED at a tooth surface. Additionally, the total electricpower consumed by the LED (“power dissipation”) disposed on the head ofthe illuminated electric toothbrush will be characterized. Forsimplicity herein, units may be discussed in either radiometric units orphotometric units, although radiometric units are preferred. Intensitycan be either luminous intensity measured in candelas (orlumens/steradian), or flux density measured in Watts/meter².

All test methods described herein are performed when the illuminatedelectric toothbrush is operated at the current normally drawn to operatethe device when the brush is fully charged and turned on, the bristlesare moving, and the LED is illuminated.

Characteristics of the LEDs of the present invention are discussed morefully below.

A. Flux Density at a Representative Tooth Surface (“FDRT”)

This test is intended to represent the radiant flux density projectedonto a tooth surface in W/m². A detector calibrated in Watts having adetector aperture area of less than about 3.14, 1.77, 1.54, 1.33, 1.23,1.13, 1.04, 0.95, 0.87, 0.79, 0.70, 0.64, 0.50, and/or 0.46 cm² and/orgreater than about 0.28, 0.31, 0.32, 0.33, 0.38, 0.44, 0.46, and/or 0.50cm² and a detector aperture diameter of at least about 0.60, 0.63, 0.64,0.70, 0.76, 0.80, 0.90, 0.95, 1.00, 1.05, 1.10, 1.15, and/or 1 cm and/orless than about 2.0, 1.50, 1.40, 1.30, 1.25, 1.20, 1.15, 1.10, 1.00 cm,and the detector aperture has a distance (“detector distance”) ofgreater than about 0.55, 0.60, 0.63, 0.64, 0.66, 0.68, 0.70, 0.72, 0.74,0.76, 0.80, 0.85, 0.90 and/or 1.0 cm, and/or less than about 2.0, 1.5,1.4, 1.3, 1.25, 1.20, 1.15, 1.10, 1.05 and/or 1.0 cm from the lightemitting point of the LED. Traditionally, the detector comprises an iristhat can provide a detector aperture area of the desired size. The LEDshould be positioned facing the detector aperture, and the mechanicalaxis of the LED should pass through the center of this detectoraperture. The detector measures radiant flux (Watts) at the detector.The detector measures the radiant flux over the entire detector aperturearea. Therefore, the resulting number is a total value of the radiantflux. The FDRT is the total value of the radiant flux divided by theSpherical Area of the cap 1109 (as shown in FIG. 20 which illustratesthe geometrical relationship between the LED and the surface to beexposed to light). The spherical area of the cap can be calculated bythe following equations:S=2πR(R−l)where:R=√{square root over (l²+d²/4)}

-   -   S=spherical area of the cap    -   l=detector distance    -   d=diameter of detector aperture area.        FDRT=Total Radiant Flux (Watts)/S        This radiant flux (Watts) is divided by the spherical area of        the cap to result in flux density at a representative tooth        surface (W/m²). An example of a device suitable for measuring        the FDRT includes the OL 730CV Radiometer/Photometer        manufactured by Optronic Laboratories, Inc. of Orlando, Fla. As        illustrated in FIG. 21 detector distance “l” (as shown at 1200)        is the distance between the light emitting point 1205 of LED        1275 and the entrance aperture 1201 of detector 1203. This        detector distance “l” (as shown at 1200) is measured from the        light emitting point 1205 of the LED 1275 to the plane of the        detector aperture 1201 of the detector 1203.

The FDRT of the inventive illuminated electric toothbrush is from atleast about 30, 35, 40, 45, 50, 55, 60, 70, and/or 100 mW/cm² and/orless than about 300, 250, 200, 150, and/or 100 mW/cm² or any combinationof these. It is believed that toothbrushes comprising LEDs thatindividually emit light at the aforementioned FDRT can result inwhitening and other oral care benefits when used in the mouth alone orin combination with other oral care compositions. To achieve these oralcare benefits at least one of the LEDs disposed on the head of thetoothbrush must emit light having an FDRT of at least about 30 mW/cm².Light having a higher FDRT may also result in whitening or other oralcare benefit, however if 300 mW/cm² is exceeded a user may need to takesafety measures to prevent damage to the oral cavity.

B. Percent Total Luminous Flux within a Solid Angle

In one embodiment of the LED of the electric toothbrush, at least about75%, 80%, 85%, 90%, 95%, 100% of the total power (watts) of the LED iscontained within the solid angle with a vertex in the center of the LEDof at least about 0, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.9, 0.95,and/or 1 steradian (“sr”) and/or less than about 6.3, 5.5, 5, 4.5, 4,3.5, 3, 2.5, 2, 1.5, 1.3, 1.2, 1.1, and/or 1 sr. The solid angle havinga vertex in the light emitting point of the LED can be calculated usingthe equations below:α=S/R ²=2πh/R,where:h=R−α andR=√{square root over (a²+b²/4)}

-   -   α=solid angle (sr)    -   S=spherical area of the cap    -   a=axial distance    -   b=diameter of the dimensional area

These calculations are similar to the calculations as used above tocalculate the FDRT, and the axial distance and dimensional area havesimilar values to the detector distance and detector area, however nodetector is present in the calculation of the solid angle.

A diagram of the void space within which the LED emits light towards thesurface to be exposed to light is shown in FIG. 20. The elements of theequation are depicted in FIG. 20 wherein “α” is the solid angle (shownat 1110) with a vertex (shown at 1111) in the light emitting point 1113of the LED 1175. “a” (illustrated in FIG. 20 at 1101) is the verticaldistance between the emitting surface of the LED and the surface to beexposed to the light emitting from the LED (“axial distance”), “b”(shown at 1103) is the diameter of a circular area comprising the LED,and “S” (shown at 1109) is the spherical area of the cap. “h” (shown at1105) equals “R” (shown at 1107) minus “a” (shown at 1101). “b” can beat least about 0.60, 0.63, 0.64, 0.65, 0.70, 0.76, 0.80, 0.90, 0.95and/or 1.00 cm, and/or less than about 2.0, 1.50, 1.40, 1.30, 1.25,1.20, 1.15, 1.10, 1.05 and/or 1.00 cm. “a” can be greater than about0.55, 0.60, 0.63, 0.64, 0.66, 0.68, 0.70, 0.72, 0.74, 0.76, 0.80, 0.85,0.90 and/or 1.00 cm, and/or less than about 2.0, 1.50, 1.40, 1.30, 1.25,1.20, 1.15, 1.10, 1.05 and/or 1.00 cm.

To determine the percent of power within the solid angle, first, thetotal power emitted from the LED must be measured, and second, the powerwithin a particular solid angle area must be measured. Finally, thepercent power within a particular solid angle is calculated. The totalpower emitted from the LED can be determined by either thegoniophotometer method and/or the integrating sphere method. Thegoniophotometer method allows for the total radiant flux to be measuredin Watts (when the goniophotometer is calibrated in Watts). The rotatingdetector of the goniophotometer scans the surface of a spherical shapedarea surrounding the LED. The partial fluxes dΦ incident on each elementdA of the surface represent a total radiant flux:E(θ,φ)=dΦ/dAWhich can be weighted and integrated to give the value of the totalradiant flux Φ, Φ = ∫_((A))E𝕕A

Another method of measuring the total radiant flux from an LED is to usean integrating sphere (calibrated in Watts) to compare the tested LED toa standard LED with a similar spatial and spectral power distribution.If no perfectly matches standard is available, a correction for colorcan be calculated; however a correction for spatial power differences ismore difficult to calculate. Most integrating spheres are no more than10 cm in diameter. Therefore, an auxiliary LED of the same type shouldbe inserted into the integrating sphere to allow for a correction to beapplied for the self-absorption of the test LED. Spheres with twoentrance and one exit port for the detector should work. Both of thesemethods are described in CIE 127 (1997) entitled “Measurement of LEDs”,which is published by the International Commission of Illumination.

Second, the power within a particular solid angle is measured. To choosethe solid angle within which the power is measured, the axial distanceand diameter of dimensional area for the desired solid angle must bedetermined using the aforementioned equations. The axial distance valuecorresponds to the detector distance value, and the diameter of thedimensional area value corresponds to the detector aperture area value.By choosing these values when performing the test, the power within thedesired solid angle is measured. If the detector has been calibrated inWatts, this results in total radiant flux within the desired solidangle.

The measurement of total radiant flux (within a particular solid angle)of the LED involves a detector calibrated in Watts having a circularaperture 1201 with an area of less than about 3.14, 1.77, 1.54, 1.33,1.23, 1.13, 1.04, 0.95, 0.87, 0.79, 0.70, 0.64, 0.50, and/or 0.46 cm²and/or greater than about 0.28, 0.31, 0.32, 0.33, 0.38, 0.44, 0.46,and/or 0.50 cm², and a detector aperture diameter of at least about0.60, 0.63, 0.64, 0.70, 0.76, 0.80, 0.90, 0.95, 1.00, 1.05, 1.10, 1.15,and/or 1 cm and/or less than about 2.0, 1.50, 1.40, 1.30, 1.25, 1.20,1.15, 1.10, 1.00 cm. The LED should be positioned facing the detectoraperture 1201 at a detector distance 1200 from the light emitting point1205 of the LED 1275 of about 0.55, 0.60, 0.63, 0.64, 0.66, 0.68, 0.70,0.72, 0.74, 0.76, 0.80, 0.85, 0.90 and/or 1.00 cm, and/or less thanabout 2.0, 1.50, 1.40, 1.30, 1.25, 1.20, 1.15, 1.10, 1.05 and/or 1.00cm. The mechanical axis of the LED should pass through the center ofthis detector aperture.

Finally, the percentage of light emitted within the desired solid angleis calculated by the equation:$\frac{{Total}\quad{Radiant}\quad{Flux}\quad{Within}\quad{the}\quad{Desired}\quad{Solid}\quad{Angle}}{{Total}\quad{Radiant}\quad{Flux}} = {\%\quad{of}\quad{Light}\quad{Emitted}\quad{Within}\quad{the}\quad{Desired}\quad{Solid}\quad{Angle}}$Total Radiant Flux Within the Desired Solid Angle/Total Radiant Flux=%of Light Emitted Within the Desired Solid AngleC. Half Angle and/or Viewing Angle

Another method for determining if a illuminated electric toothbrushemits light having the desired characteristics is to examine the halfangle and/or viewing angle of the LED. As described herein the halfangle is two times the included angle (in degrees) between the peak andthe point on one side of the beam axis at which the luminous intensityis fifty percent of the maximum or half of the beam angle. This can alsobe referred to as the viewing angle. The smaller the half angle the morefocused the light. The more focused the light emitting from the LED, theless light is needed to achieve the desired luminous intensity and/orFDRT. Having a more focused angle of light results in less light wastedfrom shining in non-preferred directions, i.e. shining into the bristlesareas. If light is shined in non-preferred directions, more light willbe required to achieve the desired luminous intensity or FDRT, oftenresulting in increased heat levels. Increased heat emission from theilluminated electric toothbrush can result in damage to the teeth andtissues in the oral cavity. The half angle (2θ½) of the LED can be lessthan about 50°, 49°, 48°, 47°, 46°, 45°, 44°, 43°, 42°, 41°, 40°, 38°,36°, 34°, 32°, 30°, and/or 28° and/or greater than about 0° and/or 5°.

D. Emission Temperature

Using an LED on the head of a toothbrush, which is then placed into theoral cavity for brushing and/or treating the teeth, may introduce heatas well as light into the oral cavity. The light can be absorbed by thesurface of the tooth, thereby generating additional heat at the toothsurface. If heat is generated within the oral cavity, the pulp chamberof the tooth can be increased, which may result in pulpitis or otherdamage to the oral cavity. To avoid causing damage in the oral cavity,the temperature of the surface of the teeth should remain less thanabout 43° C., 40° C., 39° C., 38° C., 37° C., 36° C., 34° C., 30° C.,and /or 25° C. If the temperature of the surface of the teeth isincreased beyond the aforementioned temperatures, the pulp chamber ofthe tooth may be overheated, thereby resulting in pulpitis. Therefore,the light emitted by the illuminated electric toothbrush should notproduce heat that raises the temperature of the surface of the teethgreater than about 43° C., 40° C., 39° C., 38° C., 37° C., 36° C., 34°C., 30° C., and /or 25° C. In one embodiment the temperature of thesurface of the teeth is kept below about 43° C. by using a standard LEDand providing a continuous forward current less than about 200 milliamps(“mA”) to the standard LED.

The temperature generated at the surface of the teeth resulting fromexposure to light emitted from the illuminated electric toothbrush isthe “emission temperature.” The emission temperature can be measured bydevices known in the art such as a thermo-couple 1315 (as shown in FIG.22). One thermo-couple suitable for use in the present test method isthe SC-GG-T-30-36 thermo-couple manufactured by Omega Engineering, Inc.The thermo-couple can be attached, preferably with adhesive, to thesurface of the tooth exposed to light emitting from the LED.Alternatively, the temperature at the surface of the tooth can bemeasured after exposure to the light, so long as the thermo-couple istouched to the tooth and the temperature reading is completed within atesting time of less than about 10, 9, 8, 7, 6, 5, 4, 3, 2, 1 seconds ofterminating exposure of the tooth to the light. One method of measuringtemperature after exposure to the light is terminated is by using astandard cotton swab to apply and hold the thermo-couple on the toothfor the duration of the testing time to gather the temperature data.Additionally, a unit 1317 which translates the data from thethermo-couple into temperature in degrees can be used; hand held unitHH5-08 manufactured by Omega Engineering, Inc. is suitable to be usedwith aforementioned thermo-couple to translate data received from thethermo-couple into temperature in degrees. This testing is performed invitro on standard extracted human or bovine tooth 1301 samples, withinan incubator set at 32° C. The test is performed within a incubator setat 32° C. to replicate the normal base temperature of a tooth placed inthe mouth. A suitable incubator for this test is the THELCO 3DG, catalog#51221122 available from the Jouan Group of Companies. The tooth isplaced in cast aluminum stand 1319 comprising a piece of cast aluminumwith a space removed for placement of the tooth. The cast aluminum stand1319 connects the tooth 1301 to a heat sink 1321. A heat sink suitablefor use in the present test method includes heat sink 11-5602-48 VIS#031608 manufactured by Aavid Thermalloy. A power supply (not shown) canbe provided to the heat sink. The “emission distance” is the distance1303 between the light emitting point 1305 of the LED 1375 and thesurface of the tooth 1301. The emission distance 1303 can be less thanabout 3.14, 1.77, 1.54, 1.33, 1.23, 1.13, 1.04, 0.95, 0.87, 0.79, 0.70,0.64, 0.50, and/or 0.46 cm and/or greater than about 0.28, 0.31, 0.32,0.33, 0.38, 0.44, 0.46, and/or 0.50 cm from the surface of the tooth.The light emitting point 1305 of the LED 1375 is placed at an emissiondistance of less than about 3.14, 1.77, 1.54, 1.33, 1.23, 1.13, 1.04,0.95, 0.87, 0.79, 0.70, 0.64, 0.50, and/or 0.46 cm and/or greater thanabout 0.28, 0.31, 0.32, 0.33, 0.38, 0.44, 0.46, and/or 0.50 cm from thesurface of the tooth 1301, and the illuminated electric toothbrush 1313is turned on; thereby operating the LED 1375 and illuminating thesurface of the tooth 1301. The tooth 1301 is then exposed to lightemitting from the LED 1375 for an emission time of less than about 15,14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, and/or 0 minutes and thetemperature of the tooth 1301 is measured by the standard thermo-couple1315. The thermo-couple can be attached to a separate hand-held unit1317 to translate the readings from the thermocouple 1315 intotemperature readings. The emission temperature should not exceed about43° C., 40° C., 39° C., 38° C., 37° C., 36° C., 34° C., 30° C., and /or25° C.

E. Power Dissipation

Additionally, to avoid damage to the oral cavity due to excessive heatgeneration, the total electric power consumed (“power dissipation”) bythe LED disposed on the head of the illuminated electric toothbrushshould not exceed about 2, 1.5, 1, 0.95, 0.9, 0.85, 0.8, 0.75, 0.7, 0.5,0.4, 0.3, 0.2, 0.1 Watts (“W”).

F. Examples of Embodiments of the Invention

Luminous intensity of at least about 7 candelas and/or FDRT of at leastabout 30 mW/cm² can be achieved in the inventive illuminated electrictoothbrush comprising a standard LED by increasing the forward currentbeyond that recommended by the manufacturer (“overpowering”), includingmore than one light emitter in the LED, and/or pulsing the light emittedfrom the LED, or any combination of these. Overpowering of the LED canshorten the life span of the LED. The amount the life span of the LED isshortened depends on the level of current used to overpower the LED andthe characteristics of LED. However, this shortened life span will stillexceed what is needed for use on a toothbrush, as a toothbrush is adisposable and/or replaceable item. In one embodiment the LED isdisposed on a replaceable portion of the toothbrush, and can thereforebe replaced if desired.

As used herein, the term “light” is intended to encompass the spectrumof both visible and non-visible (e.g., ultraviolet and infra-red) light.This spectrum may extend from light having a dominant or centroidwavelength of about 10 nm (far ultraviolet) to light having a centroidwavelength of 10⁶ nm (infrared), or the spectrum may include visiblelight having a centroid wavelength between about 370 nm and about 770nm. Further, the spectrum may include visible light having a centroidwavelength between about 370 to about 500. As used herein, the term“centroid wavelength” is intended to refer to the wavelength whichrepresents the perceived color of the light. This may be different thanthe peak wavelength which is the wavelength at which the radiantintensity of the LED is maximum. For LEDs, the dominant or centroidwavelength can be determined by the equations:λ_(c) = ∫_(λ_(min))^(λ  max )I(λ) ⋅ λ ⋅ 𝕕l/∫_(λmin)^(λmax)I(λ) ⋅ 𝕕λFor continuous spectrums, and$\lambda_{c} = {\sum\limits_{i}{I_{i}{\lambda_{i}/{\sum\limits_{i}I_{i}}}}}$For discrete spectrums.Wherein I is illumination intensity and λ is wavelength.

These equations are further described in CIE 127 (1997) entitled“Measurement of LEDs”, which is published by the InternationalCommission of Illumination. The spectral (e.g., peak wavelength),photometric (e.g., luminous intensity), radiometric (e.g., radiantintensity), and calorimetric (e.g., dominant wavelength) characteristicsof the LEDs can be measured using devices known in the art, such as OL730CV Radiometer/Photometer manufactured by Optronic Laboratories, Inc.of Orlando, Fla. Some light may not have a dominant or centroidwavelength (e.g., white light).

The inventive illuminated electric toothbrush comprises LEDs that emitlight having a luminous intensity of at least about 7, 10, 15, 20, 30,and/or 40 and/or less than about 60, 50, 45, and/or 40 Candelas or anycombination of these, or a FDRT of at least about 30, 35, 40, 45, 50,55, 60, 70, and/or 100 mW/cm² and/or less than about 300, 250, 200, 150,and/or 100 mW/cm² or any combination of these.

One embodiment of the illuminated electric toothbrush comprises an LEDas shown in FIG. 1. FIG. 1 shows a cross section of LED package 11comprising a lens 3, a single light emitting dice 5, a wire bonding 7, apositive lead 21 and negative lead 9, and a Longitudinal axis L. Varioustypes of semi-conductor substrates having light emitting properties canbe used in LEDs of the claimed invention. One type of semi-conductorsubstrate having a light emitting property is a dice. A dice is a singlesemi-conductor substrate having light emitting properties. It iscontemplated that the LED disposed on the head of the inventiveilluminated electric toothbrush can comprise any type of semi-conductorsubstrate having light emitting properties, including but not limited toa dice, so long as the illuminated electric toothbrush provides lighthaving the desired properties described herein. The LED can have adiameter of at least about 0.5, 1, 2, 3, 4, 5, and/or 6 mm and/or lessthan about 5, 10, 15, and/or 20 mm.

Light can emit from many surfaces of the light emitting point of an LED.However, for simplicity hereinafter all measurements of the distancefrom the light emitting point and/or surface of the LED refer to thefront surface of the semi-conductor substrate, such as the front surfaceof the dice 5. Light emits from a surface of the dice and is directed tothe lens 3 of the LED. Therefore, to measure a distance from the lightemitting point of a semi-conductor substrate, the front surface of thelight emitting element of the semi-conductor substrate must beidentified. In one embodiment of the illuminating electric toothbrushthe front surface of the light emitting element of the LED is thesurface of the dice 5 (as shown in FIG. 1). Therefore, all measurementsof distance from this embodiment of a light emitting surface begin withthe front surface of dice 5.

Overpowering the LED results in the desired luminous intensity and/orFDRT because, luminous intensity and/or FDRT of a LED increases, withinlimits, as forward current input increases. Therefore, the luminousintensity and/or FDRT levels desired for the inventive illuminatedelectric toothbrush can be achieved by increasing the current to astandard LED beyond that recommended by the manufacturer. Increasing thecurrent twice the maximum recommended by the manufacturer will almostdouble the luminous intensity and/or FDRT, while still resulting in alifespan of the LED acceptable for use in an illuminated electrictoothbrush. A standard driver can be used to deliver the chosen currentlevel to achieve the desired luminous intensity and/or FDRT. A voltageor current driver suitable for use with the present invention is theZXSC310 Single or Multi Cell LED Driver manufactured by ZetexSemiconductors, Oldham, UK. The minimum current to achieve the desiredluminous intensity and/or FDRT can be greater than the maximum currentrecommended by the manufacturer for continuous operation, two times themaximum recommended by the manufacturer for continuous operation, orthree times the maximum recommended by the manufacturer for pulsedoperation. At a maximum the current can be increased to the level whichcauses immediate failure of the LED. One embodiment of the inventioncomprises a standard LED which delivers the desired luminous intensityand/or FDRT via a continuous forward current greater than about 35 mA,40 mA, 45 mA, 50 mA, 55 mA, 60 mA, 65 mA, 70 mA, 75 mA, 80 mA, 90 mA,100 mA, 150 mA and/or 200 mA and/or less than about 700 mA, 600 mA, 500mA, 400 mA, 300 mA, 250 mA, 200 mA, 150 mA, 100 mA, 90 mA, 80 mA, 75 mA,70 mA, 65 mA, 60 mA, 55 mA, 50 mA, 45 mA, 40 mA, and/or 35 mA. In oneembodiment the minimum continuous current level can be the maximumcontinuous current rating for continuous operation, and the maximumcontinuous current level can be about the current causing immediatefailure of the LED. Although the luminous intensity and/or FDRT doesincrease as the current increases, there is a point at which thiscorrelation levels out, and further current increase does not result inluminous intensity and/or FDRT increase. This exact point depends on theproperties and design of the LED. Additionally, as time passes and theLED is exposed to currents beyond that recommended by the manufacturer,the luminous intensity and/or FDRT begins to fade. One way ofmaintaining the desired luminous intensity and/or FDRT includes, but isnot limited to, further increasing the current in order to maintain thesame luminous intensity and/or FDRT. Although the current is increasedto the standard LED to achieve the desired luminous intensity and/orFDRT, the current used is still lower than traditionally used for highpower non-standard LEDs. Therefore, the heat generated by the standardLEDs does not increase the temperature of the surface of the teeth aboveabout 43° C.

Stabilizing the current of the LED in a standard driver design doespartially stabilize the luminous intensity and/or FDRT over time sincethe current stays the same as the LED decays. However, as the LED decaysthe current may need to be increased to maintain the same level ofluminous intensity and/or FDRT. One way of maintaining constant luminousintensity and/or FDRT as the LED decays is to measure the luminousintensity and/or FDRT emitted from the LED with a built in sensor andadjust the current according to the measured value. Adjusting thecurrent as the LED decays results in an illuminated electric toothbrushwhich continues to deliver light at the specified luminous intensityand/or FDRT over time. Another way of maintaining approximately the sameluminous intensity and/or FDRT without including a built in sensor, isto include a timing circuit which increases the current to the LED overtime as the LED decays. This can maintain approximated steady luminousintensity and/or FDRT via a simple design, and with minimal additionalexpense. A voltage or current driver suitable for use with the presentinvention is the ZXSC310 Single or Multi Cell LED Driver manufactured byZetex Semiconductors, Oldham, UK.

FIG. 2 shows a another means for achieving the levels of luminousintensity and/or FDRT in the inventive illuminated electric toothbrushby including more than one light emitter such as multiple dices. Thisembodiment of the invention has a single light output, the lens 3, andone positive lead 21 and one negative lead 9. However, this singlestandard LED package contains more than one light emitter and more thanone semi-conductor substrate. All light from emitting sources iscombined to result in a single light output at lens 3 of LED package 15.The single LED package 15 has multiple light emitting dices 5 and 17 anda wire bonding 7. These dices can be electrically connected in parallelor in series. When they are connected in series, all currentconsiderations are the same as for one single dice. The total voltagewill be approximately n×V_(i) where n=number of dices, and V_(i)=forwardvoltage for a single dices. If the dices are connected in parallel, thetotal current will be approximately n×I_(i) and the total voltageapproximately that of a single dice. Serial connection works wellbecause it adjusts for differences between the dices. When the dices areconnected in series, they automatically adjust their forward voltagesand their luminous intensity and/or FDRT become very close. In eitherarrangement the two dices LED has approximately the luminous intensityand/or FDRT of 1.6×P_(i), where P_(i) is luminous intensity and/or FDRTof a single dice. A three dices LED will likely have the luminousintensity and/or FDRT of about 2.26×P_(i). (Interference between thedices can prevent the luminous intensity and/or FDRT calculation frombeing a multiplier by the number of dice.) These dices can deliver thesame color of light, or they can have different colors of light. Forexample, a single LED could contain two dices emitting different colorsof light, for example a wavelength selected from the range of greaterthan about 370, 380, 390, 400, 425, 440, 450, 475, 480 and/or less thanabout 500 nanometers. The dices could also be selected such that thedices emit light of a different wavelength within the same color range;for example the dices could emit light having different wavelengths thatresult in the color blue. Further, the combination of the differentwavelengths of light at the single optical output of the LED (the lens)could result in a specific combination of colors that delivers an oralcare benefit. For example, two different compositions can be applied tothe teeth, each of which reacts to a different wavelength of light.Additionally, different wavelengths of light may result in differentreactions within the oral cavity; one wavelength of light may killbacteria, another wavelength of light may whiten the teeth. Some colorsare difficult to achieve by a single wavelength of light; this inventioncan be used to produce light of one of these unique colors. Thus thecombination of different colors at the single optical output may resultin a color that cannot be achieved by one dice alone. Therefore, usingdifferent colors could result in one or more oral care benefits that asingle wavelength of a single color could not achieve. However, if eachindividual light emitter emits the same light, the luminous intensityand/or FDRT of that color light from that one single LED is greater thana single standard LED emitting light of one color.

Yet another means for achieving the luminous intensity and/or FDRT ofthe inventive illuminated electric toothbrush includes providing anon-continuous or pulsing current to the LED which results in pulsed ornon-continuous light. This embodiment of the invention comprises astandard LED which provides the desired luminous intensity and/or FDRTlevel via a pulse forward current greater than about 100 mA, 125 mA, 150mA, 175 mA, 200 mA, 225 mA, 250 mA, 275 mA, 300 mA, 325 mA, 350 mA,and/or 375 mA and/or less than about 900 mA, 800 mA, 700 mA, 600 mA, 500mA, 400 mA, 375 mA, 350 mA, 325 mA, 300 mA, 275 mA, 250 mA, 225 mA, 200mA, 175 mA, 150 mA, 125 mA, and/or 100 mA. In one embodiment the pulsedforward current is greater than about the maximum current rating forpulsed operation and less than about the current causing immediatefailure of the LED. The minimum luminous intensity and/or FDRT of thelight pulses can be that of continuous light, and the maximum luminousintensity and/or FDRT is Pc/Q where Pc is the luminous intensity and/orFDRT of continuous light and Q is the cycle ratio. The cycle ratioequals the duration of the pulse divided by the time period betweenpulses. The inventive cycle ratio is from about 0.01, 0.10, 0.25, 0.40,and/or 0.50 to about 0.50, 0.60 0.75, 0.80, and/or 0.99. The frequencyof the light pulses can be about 0.01 Hz, 1 Hz, 10 Hz, 100 Hz, 500 Hz,or 1 MHz to about 1 MHz, 10 MHz, 100 MHz, 500 MHz, 1 GHz, or 10 GHz. Thecurrent amplitude for the pulsed operation of the LED can go from aboutI_(maxp) to about 10 I_(maxp), where I_(maxp) is the absolute maximumcurrent rating for pulsed operation, or from about I_(max) to about 20I_(map), where I_(max) is the maximum current rating for continuousoperation. Pulsing the current to the LED results in a reduction of theLED's power dissipation, and therefore prolonged battery life, as wellas an increase in light brightness, and/or luminous intensity and/orFDRT. The improved battery life and increased brightness can varydepending on the properties and design of the LED.

In one embodiment, the illuminated electric toothbrush includes anelongated body portion or handle, a head, and a neck extending betweenthe head and the handle. One or more LEDs are provided on the head,preferably adjacent to, on, and/or in, one or more static or movingbristle holders having a plurality of bristles thereon. The bristles maybe formed into one or groups of tufts.

The head includes a longitudinal axis, one or more moving bristleholders and, optionally, one or more static or fixed bristle holders.The moving bristle holders may rotate, swivel, gyrate, oscillate,linearly reciprocate, or undergo any combination of motions. The type ofmotion provided by the electric toothbrushes of the present inventioncan be widely varied. The static bristle holders and the arrangement ofthe static bristles disposed thereon can also be widely varied. Forexample, the static bristles might partially or wholly circumscribe themoving bristle holders or may be disposed in a gap between the movingbristle holders. Examples of some bristle holder motions and bristlearrangements suitable for use with the present invention are describedin US 20030126699; US 20030084525; US 20030084524; US 20030084526; andWO 03/063723; and WO 03/063722. The bristles can be made fromconventional non-elastomeric materials, such as polyethylene, or can bemade from elastomeric materials such as natural or synthetic rubbers,polyolefins, polyetheramides, polyesters, styrenic polymers,polyurethanes, etc., or a combination of materials.

The handle has a hollow portion with a motor disposed therein that isoperatively connected to the moving bristle holders. A motor isoperatively connected to the moving bristle holder when some action bythe motor results in a response in the moving bristle holder. A shaftmay extend from the motor through the neck and into at least a portionof the head. The shaft may rotate, oscillate, linearly reciprocate,gyrate, vibrate or orbit when driven by the motor in order to impart oneor more motions to the moving bristle holders. A gearing arrangement canbe provided between the motor and the shaft or between the shaft and themoving bristle holders in order to impart motion thereto. Exemplaryshaft and/or gearing arrangements are shown in U.S. Pat. Nos. 6,360,395and 5,617,601 as well as in other patents and patent publicationsreferenced herein. The handle also has a power source, such as one ormore batteries, disposed therein for powering the motor and the LED.Alternatively, the electric toothbrush may be connected to an externalpower source for powering the motor. A switch is disposed on the handlefor activating the motor and/or LEDs. The LEDs can be energized wheneverthe motor is activated. However, the toothbrush also can have more thanone switch to activate the LEDs and/or the movable bristle holder.

FIG. 3 shows an illuminated electric toothbrush 10 according to thepresent invention. The electric toothbrush can be used for personalhygiene such as brushing one's teeth and gums. As shown in FIG. 3, theelectric toothbrush includes a handle 12 a gripping portion 70, and aneck 14 attached to the handle 12. A head 16 is attached to neck 14.Typically, the head is larger than the neck 14, which is also typicallysmaller than the handle 12.

Referring now to FIG. 4, the toothbrush 10 comprises head 16,longitudinal axis 19, a handle 12, a neck 14, gripping region 72, switch52, a moving bristle holder 20 and static bristle holders 22 havingbristles 26 disposed thereon. The static bristle holders 22 are locatedon opposite sides of the moving bristle holder 20. The moving bristleholder 20 is located at the center of the head 16. The moving bristleholder preferably oscillates about an axis approximately normal to thelongitudinal axis 19 of the head 16, although other motions may beprovided as previously described. As shown in FIG. 5, the handle 12further includes a hollow portion 30 which houses a motor 32. The motor32 powers the moving bristle holder 20 through a rotatable shaft 44. Agearing arrangement is operatively interconnected between the shaft 44and the motor 32. The gearing arrangement includes a worm gear 40 and apair of step gears 42, 43. The motor 32 is operatively connected to theworm gear 40. Step gear 42 is operatively connected to step gear 43 andthe worm gear 40. A LED 75 is provided that is disposed in the interiorof the moving bristle holder 20. The LED 75 is mounted or secured to themoving bristle holder 20 so that LED 75 moves with moving bristle holder20. As shown in FIG. 6, electric power is provided to the LED 75 by theuse of a pair of electrical contacts 76 and 77 that slidingly contactdedicated contact portions defined along the underside of the movingbristle holder 20. Electrical wires (not shown) may be provided from theswitch and power source to the contacts 76 and 77 for conductingelectricity from the power source to the LED. The wires may run from thehandle 12 through the neck 14 to the head 16. Preferably, the wires aredisposed adjacent the interior wall of the neck 14 so that they do notinterfere with the movement of the shaft 44. Alternatively, the wiresmay be embedded within the neck 14.

It is contemplated that circular electrically conductive contact regions80 and 82 could be provided along the exterior of the moving bristleholder 20, which regions would be in electrical communication with thepair of fixed contacts 76 and 77 provided within the interior of thehead. The electrically conductive contact regions 80 and 82 areinsulated from each other by a non-conductive material. Electrical leads84 and 86 can be provided from the electrically conductive contactregions to the LED. FIG. 4 illustrates the LED 75 disposed on or withinthe moving bristle holder 20. In this embodiment the LED is fixedlyattached to the moving bristle holder 20 and therefore moves with thebristle holder. Preferably the tip of the LED is flush with the topsurface 23 of the moving bristle holder 20, although it may extend abovethe top surface 23 if desired. Additional LEDs can be provided in or onthe static bristle holders 22. FIG. 6 a shows a stationary LED 75 thatis connected to a pillar 91 that is stationary and fixed to the head 95at 93 of the toothbrush. The moving bristle holder 97 oscillates orrotates around the stationary LED. The positive lead 87 and the negativelead 89 can run from the LED 75 through the pillar 91 and then down thelength of the head 95 of the toothbrush to the power source (not shown).

In another embodiment, the LED 75 is disposed within an aperture or hole88 that extends through the moving bristle holder 320, as best seen inembodiment 300 as shown in FIG. 7, so that the LED is stationary and themoving bristle holder 320 oscillates or rotates about the stationary LED75. In this embodiment, the LED 75 is fixedly secured to the head 316.The LED 75 might extend partially through the hole 88 or it may bedisposed below the lower surface of the moving bristle holder 320 sothat it is completely contained within the head 316. The centerline oraxis of the LED 75 may also be the axis of rotation or oscillation forthe moving bristle holder 320. Neck 314 extends between head 316 and ahandle (not shown). The head 316 further comprises static bristles 322.

In each of the above-described embodiments, the LED is disposed in, on,below or directly adjacent the moving and/or static bristle holders sothat the light is directed onto the brushing area as efficiently aspossible. Further, the LEDs are preferably arranged so that theprinciple direction of light emission is generally perpendicular to thetop surface of the bristle holders and/or generally parallel to thedirection of the bristles of the bristle holder. In other words, the LEDis preferably arranged so that the centerline 90 of the LED is generallyperpendicular to the top surface of the head and/or bristle holder, asbest seen in FIG. 6. The centerline 90 typically passes through the lens92 or aperture of the LED. When the LED is disposed within, on, or belowa moving and/or static bristle holder, a cylindrical region or volumeabout the centerline 90 of the LED can be substantially devoid ofbristles. The area substantially devoid of bristles can be larger and/orsmaller depending on the size of the head of the toothbrush, and/or thenumber of bristles removed in the area surrounding the LED. The areasubstantially devoid of bristles can be greater than about 0.55, 0.60,0.63, 0.64, 0.66, 0.68, 0.70, 0.72, 0.74, 0.76, 0.80, 0.85, 0.90 and/or1.0 cm, and/or less than about 2.0, 1.5, 1.4, 1.3, 1.25, 1.20, 1.15,1.10, 1.05 and/or 1.0 cm. The moving bristle holder still, however,preferably has at least one ring of bristles that encircle the LED, asshown by way of example in FIG. 7. Additional bristle tufts or an innerring of bristle tufts might, however, be provided.

Referring again to FIG. 5, a switch 50 is provided to control operationof the illuminated electric toothbrush and is operatively connected tothe motor 32. The switch 50 is also configured to operate the one ormore LEDs of the toothbrush. Such operation is preferably momentary orcontinuous. When the switch 50 is closed, a circuit comprising wire 54is completed between a standard battery 60 provided within the hollowportion 30 of the handle 12 and the motor and LED 75.

In embodiment of the toothbrush 400 the LED 75 can be placed on the head416 so that it is between static bristle holder(s) 422 and movablebristle holder 420 and not aligned with an axis of rotation/oscillationof a moving bristle holder, as shown by way of example in FIG. 8 whereinthe bristles have been deleted for clarity. Head 416 is connected tohandle (not shown) by neck 414.

FIGS. 9-12 illustrate other head, bristle holder and bristleconfigurations for illuminated electric toothbrushes, all of whichcontain one or more LEDs. FIG. 9 illustrates a head 516 and a neck 514.It will be appreciated that the neck 514 extends between the head 516and a handle of the toothbrush (not shown). Disposed on the head 516 isa single moving bristle holder 520 having a plurality of bristles tufts532 disposed thereon. Disposed on a second bristle holder 522 is a LED575. FIG. 10 depicts another head 616 in accordance with the presentinvention having a plurality of bristles 632 disposed thereon. The head616 comprises a single bristle holder 620 having LED 675 disposedtherein. Neck 614 extends between head 616 and handle (not shown). FIG.11 depicts yet another head 716 having a single bristle holder 720having bristles 732 disposed thereon. A LED 775 is disposed adjacent thebristle holder 720 on the head 716. The LED 775, however, is notdisposed on bristle holder. FIG. 12 depicts still another head 816having a first bristle holder 820 that moves and a second bristle holder822 that is fixed or stationary. Both bristle holders have LEDs 875disposed thereon. The first bristle holder 820 has a plurality ofbristle tufts 832 that encircle the LED 875 disposed thereon, and thesecond bristle holder 822 has a plurality of bristle tufts 834 thatencircle the LED 875 disposed thereon. Neck 814 extends between head 816and a handle (not shown).

As shown in FIG. 13, an embodiment of the illuminated electrictoothbrush 1010 having a head 1016, neck 1014, and a handle 1012.Disposed on the head 1016 is LED 1075. The neck and handle arereleasably connected at 1015 and contain corresponding structures fortheir physical engagement and for establishing electrical communicationbetween the LED and the power source. Referring now to FIGS. 14 and 15,the head 1016 further includes a moving bristle holder 1020 and a staticbristle holder 1022. Disposed on the static bristle holder 1022 is a LED1075.

The neck 1017 separates from the handle 1012 at joint 1015. The neck1017 has two small pins or projections 1036 [in phantom] located insidethe neck end portion 1032. The small projections are dimensioned to fitinto L-shaped slots 1042 found on a mating end portion 1040 of thehandle 1012. The width of the L-shaped slots 1042 is slightly wider thanthe width of the small projections to enable the L-shaped slots toreceive the small projections. The depth of the L-shaped slots issubstantially equal to the height of the small projections so that theL-shaped slots can receive the small projections.

To connect the head and neck to the handle, the user aligns the smallprojections with a top surface 1044 of the L-shaped slots. The userpushes or presses the head 1016 down so that the small projectionscontact a bottom surface 1046 of the L-shaped slots 1042. When the smallprojections have contacted the bottom surface 1046 of the L-shapedslots, the user then turns the head 1016 and/or the neck 1017approximately 90 degrees with respect to the handle 1012 locking thehead into place, as seen in FIGS. 14 and 15. A top surface of each ofthe projections becomes locked under a top surface of each of theL-shaped slots 1042. The user thus exerts a press-and-twist action onthe cooperating pins and guide slots to put the head into a fullyattached disposition on the handle and realize a locking engagementbetween the two.

One or more electrical contacts are provided along the mating region ofthe neck and the handle to provide a releasable electrical connectionthere between.

FIG. 16 illustrates a schematic of an electrical configuration for thepresent invention. In this configuration, the LED 75 and the motor 32are powered or activated concurrently with one another by switch 50 andpower source 60. Due to the fact that an LED is included and the powerprovided by the battery may exceed that which is desired for the LED, itmay be desirable to include a standard voltage or current driver 94which can provide a constant voltage or current output to the LEDdespite changes to the input voltage or current, especially as thevoltage or current output from a battery tends to decrease over time.While the schematic shown in FIG. 16 is one embodiment, otherconfigurations can be provided. For example, separate switches might beprovided to separately activate the LED and the motor. More than one LEDmight be provided. LEDs having different spectral, photometric,radiometric, and calorimetric characteristics (e.g., different dominantwavelengths, peak wavelengths, radiometric power, etc.) might beprovided to accommodate multiple uses in a single electric toothbrush.This can also be accomplished using an LED having multiple dices (asshown in FIG. 2).

FIGS. 17 and 18 illustrate spectral distributions for various colors ofcommercially available LED light emitting unit used in the electrictoothbrushes described herein. These spectral distribution graphs arefor Luxeon™ 1-watt emitter LEDs, however these distribution patterns maybe achieved with other light emitting units. Specifically, FIG. 17 is agraph of the relative spectral power distribution for various colors ofLEDs. FIG. 17 illustrates the colors of royal blue, blue, cyan, green,amber, red-orange, and red. FIG. 18 is the relative spectral powerdistribution for a white color LED.

For tooth bleaching as well as other applications, it is often desirableto utilize a LED that provides a generally or substantially uniformdistribution of radiometric power so that each tooth receives about thesame of amount of radiometric power over the tooth surface. Therefore,embodiments of the inventive toothbrush comprise light radiationpatterns having lamberertian or bell-shaped patterns, such as shown byway of example in FIG. 19. Other radiation patterns, such as thebat-wing pattern may also be utilized. As discussed above, however, theLED may provide a wide variety of light radiation patterns in accordancewith the present invention.

The bristles of the bristle holders can be arranged to minimallyinterfere with the light emitted from the LED. Bristles can have aheight of at least about 0.5, 0.6, 0.7, 0.8, 0.9 and/or 1.0 cm, and/orless than about 2.0, 1.5, 1.4, 1.3, 1.2, 1.1, and/or 1.0 cm. However, itis contemplated that the toothbrushes of the present invention mayutilize bristle arrangements or materials that interact with the lightemitted from the LED. For example, bristles and/or the top surface ofthe bristle holder located immediately adjacent the LED could include areflective coating, such as nickel or chrome, to assist with directinglight away from the head and toward the tooth surfaces. Alternately,bristles near the LED could be formed from a transparent or translucentmaterial to further promote the transmission of light to the brushingarea. The bristles might also be colored, pigmented, or dyed togenerally match the color of the light emitted by the LED. In this way,the bristle would not absorb, but reflect, the light emitted by the LED.In addition, the use of a reflective shield that assists with directinglight toward the tooth or gum surfaces which is placed around or nearthe LED might be utilized.

As previously noted herein, the embodiment toothbrushes with LED may beused in conjunction with a whitening composition for whitening teeth,and in particular, for enhancing or accelerating the whitening functionof the composition by irradiating the brushing region either prior to,during, or after application of the whitening composition. A kit can beprovided comprising the illuminated electric toothbrush, and acomposition comprising peroxide.

Color in organic compounds is usually attributed to chromophores, whichare unsaturated groups that can undergo π electronic transitions. Lightcan activate stain chromophores (undergo electronic transition), andreduce activation energy barrier making them more susceptible to attackby bleaching. In other words, activation of color bodies via light mayenhance peroxide bleaching. Similarly, stain chromophores become moresusceptible to abrasive whitening because of light treatment whichresults in faster and better whitening. Bleaching agents penetrate intothe pores in enamel and dentin, and, therefore, both extrinsic andintrinsic color stains can be degraded and removed.

A wide variety of tooth whitening compositions may be used incombination with the electric toothbrushes described herein. The toothwhitening compositions may contain a bleaching agent, an abrasive agent,pH modifiers or any other agent that acts upon the chromophores of theteeth by mechanical or chemical action or a combination thereof. Thetooth whitening composition can be provided in the form of a solution,paste, gel, viscous liquid, solid, or other suitable form. Illustrativebleaching agents include an oxygen radical or hydrogenradical-generating compound such as metal ion free peroxides, organicperoxides, and metal ion containing peroxides. Specific, non-limitingexamples of bleaching agents include peroxides, metal chlorites,perborates, percarbonates, peroxyacids, persulfates, compounds that formthe preceding compounds in situ, and combinations thereof. Suitableperoxide compounds include hydrogen peroxide, urea peroxide, calciumperoxide, carbamide peroxide, and mixtures thereof. In one embodimentthe bleaching agent is carbamide peroxide. Suitable metal chloritesinclude calcium chlorite, barium chlorite, magnesium chlorite, lithiumchlorite, sodium chlorite, potassium chlorite, and mixtures thereof.Additional bleaching agents also include hypochlorite and chlorinedioxide. In one embodiment the bleaching agent is selected from sodiumchlorite, peroxide, sodium percarbonate, oxones, and mixtures thereof.The starting bleaching agent can be aqueous or solid material.

The amount of bleaching agent in the whitening or bleaching compositionmay vary. For example, the bleaching agent could be present in an amountof about 0.5 to about 60 weight percent, based on the total amount ofthe tooth whitening composition. If hydrogen peroxide is the bleachingagent, according to one particular embodiment, it may be present inabout 0.5 to about 40 weight percent, especially about 7 to about 15weight percent, based on the total amount of the tooth whiteningcomposition. If carbamide peroxide is the bleaching agent, according toone particular embodiment, it may be present in about 10 to about 60weight percent, based on the total amount of tooth whiteningcomposition. Typically, the radiant energy from the LED is applied whilethe composition is in contact with the tooth, however, may be appliedprior to or after application of the tooth whitening composition.

The illuminated electric toothbrush can be packaged as a kit one or morereplaceable heads containing a LED. Although the handle is discussed aspreferably battery powered, the invention also includes other well knownpower supplies such as corded for outlet connection or rechargeablebatteries and an associated brush holder/charger (not shown).

As discussed above, the various embodiments of the illuminated electrictoothbrush may be used in combination with a whitening composition. Arepresentative method of whitening teeth is as follows. After obtainingthe illuminated toothbrush and composition, the composition is appliedto the dental surface, i.e. teeth, to be whitened. Preferably, suchapplication is performed by depositing an effective amount of thecomposition on the bristle holder of the toothbrush, and then applyingthe composition to the desired surfaces to be whitened. Generally, thislatter step is performed in like fashion as brushing one's teeth.Alternatively, the tooth whitening composition might be brushed,painted, or applied to the teeth with an applicator strip. The lightemitting unit of the toothbrush is then activated and the light emittedthere from is directed to the applied composition. It will be understoodthat the various whitening techniques of the present invention includevariant strategies in which the light is directed to the dental surfacebefore, during, and after application of the composition to the dentalsurface. Preferably, a brushing operation is then performed while thelight continues to irradiate the composition applied to the dentalsurface of interest.

This whitening process is merely exemplary. The present inventionincludes a wide array of whitening techniques. Additionally, it iscontemplated that a conventional brushing operation may be performedprior to, during, or subsequent to a whitening operation.

The present invention has been described with reference to multipleembodiments. Obviously, modifications and alterations will occur toothers upon a reading and understanding of this specification. Forexample, any number of bristle holders and bristle patterns can beutilized with the present invention along with one more LED. It isintended to include all such modifications and alterations insofar asthey come within the scope of the appended claims or the equivalentsthereof.

The dimensions and values disclosed herein are not to be understood asbeing strictly limited to the exact numerical values recited. Instead,unless otherwise specified, each such dimension is intended to mean boththe recited value and a functionally equivalent range surrounding thatvalue. For example, a dimension disclosed as “40 mm” is intended to mean“about 40 mm.”

All documents cited in the Detailed Description of the Invention are, inrelevant part, incorporated herein by reference; the citation of anydocument is not to be construed as an admission that it is prior artwith respect to the present invention. To the extent that any meaning ordefinition of a term in this document conflicts with any meaning ordefinition of the same term in a document incorporated by reference, themeaning or definition assigned to that term in this document shallgovern.

While particular embodiments of the present invention have beenillustrated and described, it would be obvious to those skilled in theart that various other changes and modifications can be made withoutdeparting from the spirit and scope of the invention. It is thereforeintended to cover in the appended claims all such changes andmodifications that are within the scope of this invention.

1. An electric toothbrush having a handle, a neck attached to thehandle, and a head attached to the neck, the toothbrush comprising: amovable bristle holder having a plurality of bristles extendingtherefrom; and a light emitting element disposed in the bristle holder,wherein the light emitting element is capable of providing light havingwavelengths between about 390 nm to about 770 nm and having aradiometric power of between about 5 mW/cm² to about 200 mW/cm².
 2. Thetoothbrush of claim 1, wherein the light emitting element is an LED. 3.The toothbrush of claim 1, wherein the light emitting element is capableof providing blue light.
 4. The toothbrush of claim 1, wherein the lightemitting element is capable of providing light having wavelengthsbetween about 420 nm to about 490 nm.
 5. The toothbrush of claim 1,wherein the light emitting element is capable of providing light havingwavelengths between about 430 nm to about 480 nm.
 6. The toothbrush ofclaim 1, wherein the head is made of a transparent material.
 7. Thetoothbrush of claim 6, wherein the bristle holder is made of atransparent material.
 8. The toothbrush of claim 2, further comprising avoltage driver or a current driver capable of providing a constantvoltage or a constant current to the LED, respectively.
 9. Thetoothbrush of claim 2 further comprising a DC power supply capable ofproviding between about 0.5 to about 5 volts to the LED.
 10. Thetoothbrush of claim 1, wherein the bristles surround the light emittingelement.
 11. The toothbrush of claim 10, wherein a cylindrical volumedevoid of bristles encircles the light emitting element, and wherein adiameter of the cylindrical volume is between about 2 mm to about 8 mm.12. The toothbrush of claim 1, wherein a portion of the plurality ofbristles are formed from a translucent material.
 13. The toothbrush ofclaim 1, wherein a portion of the plurality of bristles are colored,pigmented, or dyed, such that the portion of the plurality of bristlesgenerally match the color of the light emitted by the light emittingelement.
 14. The toothbrush of claim 1, wherein a portion of theplurality of bristles are formed from an elastomeric material.
 15. Thetoothbrush of claim 1, wherein the radiometric power of the lightemitting element is between about 10 mW/cm² to about 100 mW/cm².
 16. Thetoothbrush of claim 1, wherein the radiometric power of the lightemitting element is between about 20 mW/cm² to about 60 mW/cm².